Blasting assembly



Oct. 16, 1962 J c. O'BRIEN 3,058,419

BLASTING ASSEMBLY Filed July 16, 1959 2 Sheets-Sheet 1 INVENTOR. JOHN c. O'BRIEN Oct. 16, 1962 J. c. O'BRIEN 3,058,419

BLASTING ASSEMBLY Filed July 16, 1959 2 Sheets-Sheet 2 Fig. 5.

INVENTOR.

JOHN G. O'BRIEN n: erm

3,058,419 BLASTING ASSEMBLY John C. OBrien, North Plainfield, N.J., assign'or to Atlas Chemical Industries, Inc., a corporation of Delaware Filed July 16, 1959, Ser. No. 827,510 Claims. (Cl. 102-24) This invention relates to explosive cartridge assemblies of the kind which find particular application in the field f geophysical prospecting.

eMore particularly this invention relates to a blasting assembly device to be used in combination with canned explosives in seismograph prospecting for oil.

It is an object of the present invention to provide an explosive cartridge assembly with reliable initiation and especially adapted to seismic blasting operations.

Another object of the invention is to provide a blasting assembly which will reliably detonate a base charge column under high hydrostatic heads.

A still further object of the present invention is to provide a blasting assembly unit which combines the function of primer and detonator shield.

These and other objects and advantages will become apparent from the following description and arrangement of the parts and from the accompanying drawings wherein like numerals refer to like parts.

This invention is embodied in an explosive assembly adapted for connection to a column of explosives. The assembly is divided transversely into two housing elements, the first housing element including a first detonator well and the second housing element including a second detonator Well, and a booster well with means for putting into registry the first and second detonator wells and such that when the two housing elements are completely connected, the detonator Wells are out of registry.

One specific embodiment of the invention is illustrated in the drawings, in which:

FIGURE 1 is a top plan view of the first housing element.

FIGURE 2 is a sectional elevation of the first housing element taken along line 22 of FIGURE 1.

FIGURE 3 is a top plan view of the second housing element.

FIGURE 4 is a sectional elevation of the second housing element taken along line 44 of FIGURE 3.

FIGURE 5 is an exploded view of the assembly along with a detonator, a booster, and the top portion of a canned explosive.

As shown in FIGURES 1 and 2 the first housing element 14 is a cylindrical piece including an eccentrically arranged and generally cylindrical first detonator well 6, the axial centerline of which is parallel with the axial centerline of element 14. Detonator well 6 extends from an exterior face 8 of the element through a meeting face 10. In addition, first housing element 14 includes a concentrically arranged cavity 12 the axial centerline of which is also parallel to the axial centerline of first housing element 14. Cavity 12 extends from the meeting face partly through housing element 14 and communicates with detonator well 6 which extends from cavity 12 through to the exterior face 8 of the housing element 14.

As shown in FIGURES 3 and 4, second housing element 16 is a cylindrical piece including a concentric booster well 22 adapted to receive a booster charge and extending from exterior face 20 of the housing element 16 and partly through the housing element. Second housing element 16 also includes an eccentrically arranged and generally cylindrical plug member 26 extending outwardly from a meeting face 18 of the second housing element 16, plug member 26 being of such di ameter that it fits into cylindrical cavity 12 of first housing element 14. In the specific embodiment shown the cylindrical cavity 12 of the first housing element 14 is provided with threads 24 adapted to be engaged with threads 28 which are provided on the plug member 26 of the second housing element 16.

The generally cylindrical plug member 26 of the second housing element 16 is also provided with a concentric second detonator well 30 extending through plug member 26 to booster well 22. The axial centerline of detonator well 36 of the second housing element 16 is concentric with the axial centerline of the second housing element 16.

It is now apparent that first housing element 14 may be operatively secured to the second housing element 16 to provide a blasting assembly which houses both the detonator and the booster elements of an explosive train thereby permitting association of a detonator with a booster. In addition, first detonator well 6 of first housing element 14 may be placed in registry with second detonator well 30 of the second housing element 16 in one angular relationship of housing element 14 and housing element 16 only. When the threads 24 and 28 are completely engaged so that meeting face 10 of the housingelement 14 is in contact with the meeting face 18 of the second housing element 16, the two housing elements 14- and 16 are coaxially aligned, but first detonating well 6 of first housing element 14 is out of registry with second detonator well 30 of second housing element 16.

As shown in FIGURES 4 and 5, the second housing element is provided with threaded portion adjacent its external face 20 which permits the blasting assembly to be attached to the threaded portion 40* of a canned explosive unit 31 containing, for example, nitro-carbo nitrate or other base explosive charge. A series of similar explosive units may be secured together as provided in the Lewis Patent 2,238,939 to form a rigid column of explosive cartridges which may easily be inserted into a shot hole. The assembly of this invention may be applied to the end unit.

From the exploded view of drawing, FIGURE 5, it can be seen how the instant device permits the association of detonator 34, booster element 36 and base explosive charge 31 into an effective explosive column.

In assembling the column, booster element 36 which may be a shell containing a high explosive, such as, for example, pentaerythritol tetranitrate, is placed in booster well 22 of the second housing element 16 after which second housing element 16 is threadedly attached to the top can 31 of the explosive column by means of threads 32 on element 16 and threaded well 40 of the base can explosive charge 3 1. First housing element 14 is then threadedly attached to second housing element 16 by means of threads 28 on plug member 26 and the threads 24 of eccentric cavity 12 in housing element 14. Prior to complete engagement of thread-s 24 and 28 and at a position where first detonator well 6 is in registry with second detonator well 30 detonator element 34 is inserted all the way through first detonator well 6 of the first housing element 14- and into second detonator well 30 of the second housing element 16. It will be noted that the booster element contains a concentric bore 37 which is adapted to receive the lower portion of detonator element 34.

After insertion of the detonator as hereinabove described, tthe threads 24 and 28 are completely engaged so that the meeting face 10 of housing element 14 is in contact with meeting face 18 of second housing element 16 and first detonator well 6 is out of registry with second detonator well 30 and detonator 34 is locked into position in association with booster 36.

In the preferred embodiment it can be seen that registry of detonator well 6 of the first housing element 14 and the second detonator well 30 of the second housing element 16 is provided by eccentrically mounted screw connections provided on plug member 26 of the second housing element 16 and the threaded cavity 12 of the first housing element 14, however, bayonette or other plug means may be employed for association the two housing elements 14 and 16.

It will also be noted that the blasting assembly device of the present invention is also provided with a plurality of grooved portions, 38 and 39 which are provided to permit passage of the detonator leg wires 42 about the housing elements. First housing element 14 is provided with a groove 48 across its exterior face and in addition longitudinal grooves 38 on either side of the housing element which grooves communicate with the horizontal groove 48 and provide for a substantially continuous grooved passage about the housing element. In addition second housing element 16 is provided with longitudinal grooves 39 on opposite sides of the element which grooves communicate with the longitudinal grooves 38 of the first housing element 14 when the two housing elements are completely associated and the meeting face of housing element 14 is in contact with meeting face 18 of second housing element 16. In addition, second housing element 16 is provided with a substantially circular channel 50 as shown in FIGURE 4 at is exterior face and immediately above the threads 32 on element 16.

Thus, it will be seen that in assembling the explosive column utilizing the blasting assembly of the present invention that leg wires 42 of detonator 34 may be passed out through the first detonator well 6 horizontally across the exterior face of housing element 14 in the horizontal groove 48 down one side of housing element 14 in the longitudinal groove 38 and into the longitudinal groove 39 of the second housing element. The wires are then pressed about the exterior into channel 50 and from there up the other side of the housing elements in longitudinal grooves 39 and 38. In this manner it can be seen that there is no pull exerted on the detonator 34 or the leg wires 42 and the wires may be used to lower or raise the blasting assembly into a drill hole. In addition, the groove elements as provided remove the wires from the area directly in line with the blasting column and thus tamping rods can be utilized in ramming the entire assembly into a drill hole without damaging the detonator wires.

As shown in FIGURES 2 and 3, the housing elements 14 and 16 are also provided with cut-away portions 45, 46, and 47 which have been provided in order to lighten the assembly and provide for greater ease of fabrication. The blasting assembly of the present invention may be advantageously composed of any suitable plastic rigid material such as polystyrene and it has been found that the provided cut-away portions lighten the unit and provide for better casting.

The invention has been described in the foregoing. However, variations in the blasting assembly may be provided without departing from the present invention.

I claim:

1. In a device of the character described, an assembly divided transversely into a first housing element and a second housing element, each of said housing elements having a meeting face and an exterior face, said first housing element including a first detonator well, said second housing element including a second detonator well and a booster well, said second detonator well extending through the meeting face of said second housing element to said booster well, each of said housing elements having a mutually cooperating threaded portion thereon providing a screw connecting means for engagedly connecting said housing elements and permitting said first detonator well in said first housing element to be placed into and out of registry with said second detonator well in said second housing element, said screw connecting means on said housing elements positioned eccentric to the axial center lines of both said first and said second housing elements.

2. In a device of the character described, an assembly divided transversely into a first housing element and a second housing element, each of said housing elements having a meeting face and an exterior face, said first housing element including first detonator well positioned eccentric to the axial center line of said first housing element said second housing element including a second detonator well and a booster well said second detonator well and said booster well located concentric to the axial center line of said second housing element, said second detonator well extending through the meeting face of said second housing element, each of said housing elements having a threaded portion thereon providing a screw connecting means for associating said first and said second housing elements and for placing said first detonator well in said first housing element into and out of registry with said second detonator well.

3. An assembly as in claim 2 wherein said screw connecting means for associating said first and said second housing elements are eccentric to both housing elements.

4. In a device of the character described, an assembly divided transversely into a first housing element and a second housing element, each of said housing elements having a meeting face and an exterior face; said first housing element including a generally cylindrical cavity extending from the meeting face of said first housing element and partly through said element, said cavity eccentrically arranged in relation to the axial center line of said first housing element, the axial center line of said cavity being parallel to the axial center line of said first housing element, a generally cylindical detonator well extending from said cavity to the exterior face of said first housing element, said detonator well being eccentrically arranged in relation to the axial center line of said first housing element, the axial center line of said detonator well being parallel to the axial center lines of both said cavity and said first housing element but coincident with neither, said second housing element having a booster well positioned concentric to the axial center line of said second housing element and extending from the exterior face thereof into said element, a generally cylindrical plug member eccentrically arranged in relation to the axial center line of said second housing element extending outwardly from the meeting face of said second housing element, said plug member being of a diameter such that it fits into said cylindrical cavity in said first element, the axial center line of said plug member being parallel to the axial center line of said second housing element, said plug member further including a generally cylindrical detonator well eccentrically arranged in relation to the axial center line of said plug member, said detonator well having an axial center line coincident with the axial center line of said second housing element and said booster well, said plug member fitting into said cavity of said first housing element so as to permit the meeting faces of said elements to engage and the center lines of said elements to conincide and also so as to permit rotation of said elements with respect to each other whereby said detonator Wells may be put into registry under a condition in which the axial center lines of said members are not coincident.

5. An explosive assembly device comprised of a first housing element and a second housing element, said first housing element having a detonator well, said second housing element having a detonator -well and a booster well in communication therewith, each of said housing elements having a threaded portion thereon providing a mutually cooperating screw connecting means,

5 said housing elements adapted to be engagedly connected together by said screw connecting means upon rotation of one housing element in respect to the other 2,238,939 Lewis et a1. Apr. 22, housing element, said detonator Wells 111 said housings 2,335,842 Nichols 30, being placed into and out of registry during connection 5 2,933 463 Jass May 11 of the housing elements, and the said detonator Wells 2,966,857 Toomcy Jan. 3, being positioned out of registry when said housing ele FOREIGN PATENTS ments. are completely connected. 395,822 Great Bmain July 27,

56,373 Netherlands Dec. 15,

6 References Cited in the file of this patent UNITED STATES PATENTS 

